I though that I had said gm own chevy and mazda is actually owned by Ford and has nothing to do with Toyota who in-cahoots with yamaha, but anyhoo.... I did nothing to the engine, I did not remove or modify anything, 100% stock. It is just a poor quality engine. WHen it ran it was lightning fast, but that doesn't make up for the down time I face to get it repaired, I am switching to another brand.